The airline is taking the service out of the trial stage and will install Gogo Inflight Internet on 300 American's MD-80s and Boeing 737-800s over the next two years.
Officials say the expansion will help American Airlines further enhance the travel experience and meet customers' evolving travel needs.
Passengers can use their Wi-Fi enabled devices to surf the web, check email, send instant messages and access a corporate VPN.
American was the first U.S. airline to launch the Gogo service last August.
Thousands of customers traveling on more than a dozen aircraft have taken advantage of the Internet access primarily on nonstop flights between New York JFK and San Francisco, Los Angeles, and Miami.
Gogo service prices range from about $8 to $13. Cell phone service and Voice over Internet Protocol service are not be available.